Proven measurement principle
The detection of mercury contained in the sample occurs in an optical cell made of fused silica (Suprasil). In a first step mercury is reduced to the elementary state by means of tin(II)chloride or NaBH4. Subsequently mercury is stripped from the aqueous phase with an air stream and carried into the optical cell. Here the UV absorption measurement is conducted at a wavelength of 253,7 nm.
This analytical technique called “cold vapor atomic absorption spectroscopy (CVAAS)” shows extreme sensitivity and selectivity. It has been reliable and proven for many years. In contrast to the occasionally recommended atomic fluorescence method the analytical technique utilized by the PA-2 is extremely low in interference and does not require an amalgamation step nor expensive noble gas as a carrier.